Bonding material solution and the use thereof in an automotive spot repair kit

ABSTRACT

A binder solution comprising, based on the solution,
         (A) from 30 to 50% by weight of an alkyl and/or cycloalkyl acetate of 3 to 10 carbon atoms in the alkyl and/or cycloalkyl radical,   (B) from 30 to 50% by weight of an alkoxyalkyl, cycloalkoxyalkyl, alkoxycycloalkyl and/or cycloalkoxycycloalkyl acetate of 1 to 6 carbon atoms in the alkoxy and alkyl radical and of 3 to 10 carbon atoms in the cycloalkoxy and cycloalkyl radical,   (C) from 10 to 30% by weight of an alkylaromatic compound having at least two alkyl radicals of 1 to 6 carbon atoms in the molecule,   (D) from 0.01 to 1% by weight of an alcohol of 1 to 6 carbon atoms in the molecule,   (E) from 0.005 to 1% by weight of an additive, and   (F) from 0.5 to 5% by weight of an organic solution of a (meth)acrylate copolymer having a solids content, based on the solution (F), of from 50 to 90% by weight,
 
and its use for automotive spot repair.

This application is a National Phase Application of Patent ApplicationPCT/EP01/10146 filed on 04 Sep. 2001.

The present invention further relates to the use of the novel bindersolution as a spot blender for automotive spot repair (very minorrepairs carried out in situ). The present invention additionally relatesto a novel automotive spot repair process. The present invention relatesnot least to a novel device (spot repair set) for training and for theimplementation of novel automotive spot repair processes.

With large-scale damage to motor vehicles, the normal procedure is toremove the damaged parts of the bodywork and refinish them over theirfull area. In the case of very minor damage, annoying particularly inthe case of new or high-value vehicles, such as key scratches or knocksagainst parking lot -surrounds, however, this procedure is verylaborious and not appropriate to the extent of the damage.

Minor damage is therefore preferably remedied with the aid of techniquesfor very small-scale automotive refinish. Among those in the art, thisis also known as spot repair.

The known spot repair techniques, however, have numerous disadvantagesand are difficult to carry out. In many cases, for instance, the runoutzones of the clearcoat spraymist on the original finish are too wide,which makes the visual matching of refinish and original finish moredifficult. Moreover, the repair clearcoat may break away or tear owingto poor adhesion of the refinish clearcoat to the original finish in therunout zones around the damage site. This produces clearly visible edgeswhich may even run right around the refinish clearcoat that projectsbeyond the original finish. In that case, owing to the visually strikingtransition zones, the overall effect of the refinish is that of a“plaster which has been stuck on”.

Attempts have been made to solve the problems of breakaway or tearingand of the difficulty of matching the optical properties in the runoutzones by applying what are known as spot blenders over the uncuredrefinish clearcoat. The purpose of this is to produce particularly“soft” transition zones and to prevent the refinish clearcoat tearingfrom the original finish in the edge zones. However, the spot blendersused to date lack the process reliability necessary for spot repair, sonecessitating additional work which in some cases may be considerable.Owing to these disadvantages, the known spot blenders are alsounsuitable for use in inplant spot repair of original motor vehiclefinishes at the premises of the automaker.

It is an object of the present invention to provide a novel bindersolution suitable as a spot blender for automotive spot repair, saidnovel spot blender not having the disadvantages of the prior art butinstead ensuring a high level of process reliability, very good flowoutand very good accommodation of the spraymist droplets in the runoutzones, so resulting in particularly “soft” transition zones of therefinish clearcoat. The process reliability and the optical andmechanical quality brought about by the novel spot blender should be sogood that the novel spot repair processes in question are also suitablefor the inplant spot repair of original automotive finishes at theautomaker. Not least, the novel binder solution should be toluene-freeand subject to no labelling requirements.

It is a further object of the present invention to find a novelautomotive spot repair process from which the disadvantages of the priorart are absent and which instead has a high level of process reliabilityand ensures very good flowout and very good accommodation of spraymistdroplets in the runout zones. Moreover, the refinishes produced with theaid of the novel process should have particularly “soft” transitionzones to the original finish, so that they do not stand out visuallyfrom the original finish but instead are fully matched to it.

It is yet a further object of the present invention to provide a novelspot repair set which can be provided to the paintshops for purposes oftraining and of implementing the spot repair processes, which are knownto be difficult and complex.

Accordingly, the novel binder solution has been found, which comprises,based on the solution,

-   (A) from 30 to 50% by weight of at least one alkyl and/or cycloalkyl    acetate of 3 to 10 carbon atoms in the alkyl and/or cycloalkyl    radical,-   (B) from 30 to 50% by weight of at least one alkoxyalkyl,    cycloalkoxyalkyl, alkoxycycloalkyl and/or cycloalkoxycycloalkyl    acetate of 1 to 6 carbon atoms in the alkoxy and alkyl radical and    of 3 to 10 carbon atoms in the cycloalkoxy and cycloalkyl radical,-   (C) from 10 to 30% by weight of at least one alkylaromatic compound    having at least two alkyl radicals of at least 1 to 6 carbon atoms    in the molecule,-   (D) from 0.01 to 1% by weight of at least one alcohol of 1 to 6    carbon atoms in the molecule,-   (E) from 0.005 to 1% by weight of at least one additive, and-   (F) from 0.5 to 5% by weight of an organic solution of at least one    (meth)acrylate copolymer having a solids content, based on the    solution (F), of from 50 to 90% by weight.

In the text below, the novel binder solution is referred to as the“solution of the invention” or “spot blender of the invention”.

Furthermore, the novel process for automotive spot repair has beenfound, comprising the steps of

-   (1) cleaning the damage site and its surroundings,-   (2) sanding and recleaning the damage site,-   (3) if desired, filling, sanding and cleaning the damage site,-   (4) applying a filler and flashing off the resultant filler film, or    alternatively curing the filler film and sanding and cleaning the    resultant filler coat,-   (5) applying a basecoat material to the filler film or filler coat,    flashing off the resultant basecoat film, and removing any    overspray,-   (6) applying a clearcoat material wet-on-wet to the basecoat film,-   (7) applying a spot blender, and-   (8) curing the applied films,

the basecoat material being applied hidingly by pneumatic applicationusing a spray gun from the outside, i.e. from the original finish,inward, i.e. toward the center of the damage site, and the spot blenderused comprising the solution of the invention.

In the text below, the novel process for automotive spot repair isreferred to as the “process of the invention”.

Not least, the novel spot repair set for training and for implementingthe process of the invention has been developed, comprising

-   -   metal case,    -   in the base of the case, a foam inlay with a depression in the        center and two depressions symmetrically left and right thereof,        -   the depression in the center containing a can of the            ready-to-spray solution of the invention and        -   the two depressions left and right thereof each containing a            small spray gun for implementing the process of the            invention,    -   a foam inlay in the lid of the case, containing        -   a manual and a CD-ROM which describe the process of the            invention.

In the text below, the novel spot repair set for training and forimplementing the process of the invention is called the “set of theinvention”.

Constituent (A) of the solution of the invention is at least one,especially one, alkyl and/or cycloalkyl acetate of 3 to 10 carbon atomsin the alkyl radical and/or cycloalkyl radical. The alkyl radicalpreferably contains 3 to 5 carbon atoms.

Examples of suitable alkyl radicals accordingly are propyl, isopropyl,n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl anddecyl radicals. Examples of suitable cycloalkyl radicals arecyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and norbornenylradicals.

In accordance with the invention the alkyl radicals, especially propyl,isopropyl, n-butyl, sec-butyl, tertbutyl or pentyl radicals, are ofadvantage and are therefore used with preference. Of these, the n-butylradicals are used with particular preference. The constituent (A)employed with particular preference is accordingly n-butyl acetate.

Constituent (A) is present in the solution of the invention in anamount, based on the solution, of from 30 to 50% by weight, preferablyfrom 35 to 45, and in particular from 37 to 43,% by weight.

Constituent (B) of the solution of the invention is at least one,especially one, alkoxyalkyl, cycloalkoxyalkyl, alkoxycycloalkyl and/orcycloalkoxycycloalkyl acetate of 1 to 6 carbon atoms in the alkoxy andalkyl radical and of 3 to 10 carbon atoms in the cycloalkoxy andcycloalkyl radical. Preferably, the alkoxy radical contains 1 to 3carbon atoms and the alkyl radical 2 to 4 carbon atoms.

Examples of suitable alkoxy radicals are methoxy, ethoxy, propyloxy,butoxy, pentoxy and hexoxy radicals, of which the methoxy radical isparticularly advantageous and is therefore employed with particularpreference.

Examples of suitable alkyl radicals are those described above, of whichthe propyl radical is particularly advantageous and is thereforeemployed with particular preference.

Examples of suitable cycloalkyl radicals are those described above,especially the cyclohexyl radical.

Examples of suitable cycloalkoxy radicals are cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and norbornenyl radicals, especially thecyclohexyloxy radical.

In accordance with the invention, alkoxy radicals and alkyl radicals areof advantage. The constituent (B) employed with particular preference isaccordingly methoxypropyl acetate, especially 1-methoxypropyl 2-acetate.

Constituent (B) is present in the solution of the invention in anamount, based on the solution, of from 30 to 50, preferably from 35 to45, and in particular from 37 to 43,% by weight.

Constituent (C) of the solution of the invention is at least one,especially one, alkylaromatic compound having at least two, especially 2to 3, alkyl radicals of at least 1 to 6 carbon atoms. Examples ofsuitable alkyl radicals are those described above. Of these, the methylradical is particularly advantageous and is therefore used withparticular preference in accordance with the invention. Examples ofhighly suitable alkylaromatic compounds are, therefore, o-, m- andp-xylene and also the technical-grade mixtures of these isomers,referred to collectively below as “xylene”, mesitylene, pseudocumene andhemellitol, but especially xylene.

Constituent (C) is present in the solution of the invention in anamount, based on the solution, of from 10 to 30, preferably from 15 to25, and in particular from 17 to 23,% by weight.

Constituent (D) of the solution of the invention is at least one,especially one, alcohol of 1 to 6 carbon atoms in the molecule,preferably methanol, ethanol, propanol and/or isopropanol, butespecially ethanol. The ethanol may also be denatured. The denaturant;for example, may be methylethyl ketone employed in an amount of from 1to 2% by weight, based on ethanol and methyl ethyl ketone.

Constituent (D) is present in the solution of the invention in anamount, based on the solution, of from 0.01 to 1, preferably from 0.1 to0.4, and in particular from 0.1 to 0.3% by weight.

Constituent (E) of the solution of the invention is at least oneadditive. It is preferred to use additives which are known and customaryin the field of coating materials. Preference is given to the use ofsurface-active substances such as wetting agents or leveling agents.

Examples of suitable wetting agents (E) are decalin, tetralin,siloxanes, fluorine compounds, carboxylic monoesters, phosphates,polyacrylic acids and their copolymers, or polyurethanes. For furtherdetails, reference is made to the textbook “Lackadditive” [Coatingsadditives] by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, andto Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart,N.Y., 1998, page 409, “wetting agents” and page 602, “leveling-agents”.

The additive is present in the solution of the invention in an amount,based on the solution, of from 0.005 to 1, preferably from 0.01 to 0.05,and in particular from 0.02 to 0.04% by weight.

Constituent (F) is at least one, especially one, organic solution of atleast one, especially one, (meth)acrylate copolymer. Preference is givento the use of methacrylate -copolymers. Methacrylate copolymers employedwith particular preference have a hydroxyl number >100, especially >120,mg KOH/g. The organic solution has a solids content of from 50 to 90,preferably from 55 to 85, in particular from 60 to 70,% by weight, basedin each case on the solution (F).

Based in each case on their total amount, the (meth)acrylate copolymerscontain in copolymerized form up to 90, preferably up to 88, morepreferably up to 86, with particular preference up to 84, with veryparticular preference up to 82, and in particular up to 80,% by weightof hydroxyl-containing olefinically unsaturated monomers (a1).

Examples of suitable hydroxyl-containing olefinically unsaturatedmonomers (a1) are 2-alkylpropane-1,3-diol mono(meth)acrylates such as2-methyl-, 2-ethyl-, 2-propyl-, 2-isopropyl- or2-n-butyl-propane-1,3-diol mono(meth)acrylate.

Further examples of suitable hydroxyl-containing olefinicallyunsaturated monomers (a1) are hydroxyalkyl esters of acrylic acid,methacrylic acid or another alpha,beta-ethylenically unsaturatedcarboxylic acid, which (i) are derived from an alkylene glycol which isesterified with the acid, or (ii) are obtainable by reacting the acidwith an alkylene oxide such as ethylene oxide or propylene oxide;especially hydroxyalkyl esters of acrylic acid, methacrylic acid,crotonic acid or ethacrylic acid, in which the hydroxyalkyl groupcontains up to 20 carbon atoms, such as 2-hydroxyethyl, 3-hydroxypropyl,-3-hydroxybutyl, 4-hydroxybutyl acrylate, methacrylate, ethacrylate orcrotonate; 1,4-bis(hydroxymethyl)cyclohexane oroctahydro-4,7-methano-1H-indenedimethanol monoacrylate,monomethacrylate, monoethacrylate or monocrotonate; or reaction productsof cyclic esters, such as epsilon-caprolactone, for example, and thesehydroxyalkyl esters; or olefinically unsaturated alcohols such as allylalcohol; or polyols such as trimethylolpropane monoallyl or diallylether or pentaerythritol monoallyl, diallyl or triallyl ether. Thesehigher-functional monomers (a1) are generally used only in minoramounts. In the context of the present invention, minor amounts ofhigher-functional monomers (a1) are those amounts which do not lead tocrosslinking or gelling of the (meth)acrylate copolymers, unless it isintended that they should be in the form of crosslinked microgelparticles.

Further suitable monomers (a1) are ethoxylated and/or propoxylated allylalcohol, which is sold by the company Arco Chemicals, or 2-hydroxyalkylallyl ethers, especially 2-hydroxyethyl allyl ethers. Where used, theyare employed preferably not as sole monomers (a1) but instead in anamount of from 0.1 to 10% by weight, based on the (meth)acrylatecopolymer.

Also suitable are reaction products of acrylic acid and/or methacrylicacid of the glycidyl ester of an alpha-branched monocarboxylic acid of 5to 18 carbon atoms per molecule, especially a Versatic® acid, or,instead of the reaction products, an equivalent amount of acrylic acidand/or methacrylic acid which is then reacted during or after thepolymerization reaction with the glycidyl ester of an alpha-branchedmonocarboxylic acid of 5 to 18 carbon atoms per molecule, especially aVersatic® acid (cf. Römpp, opp. cit., “Versatic® acids”,pages 605 and606).

Furthermore, the (meth)acrylate copolymers include further olefinicallyunsaturated monomers (a2) whose proportion is at least 10, preferably atleast 12, more preferably at least 14, with particular preference atleast 16, with very particular preference at least 18, and in particularat least 20,% by weight.

Examples of suitable monomers (a2) are

Monomers (a21):

(Meth)acrylic esters which are essentially free from acid groups, suchas (meth)acrylic alkyl or cycloalkyl esters having up to 20 carbon atomsin the alkyl radical, especially methyl, ethyl, propyl, n-butyl,sec-butyl, tert-butyl, hexyl, ethylhexyl, stearyl and lauryl acrylate ormethacrylate; cycloaliphatic (meth)acrylic esters, especiallycyclohexyl, isobornyl, dicyclopentadienyl,octahydro-4,7-methano-1H-indene-methanol or tert-butylcyclohexyl(meth)acrylate; (meth)acrylic oxaalkyl or oxacycloalkyl esters such asethyltriglycol (meth)acrylate and methoxybligoglycol (meth)acrylatehaving a molecular weight Mn of preferably 550 dalton or otherethoxylated and/or propoxylated, hydroxyl-free (meth)acrylic acidderivatives: (further examples of suitable monomers (a2) of this kindare known from the laid-open specification DE 196 25 773 A 1, column 3,line 65 to column 4, line 20). In minor amounts these may containhigher-functional (meth)acrylic alkyl or cycloalkyl esters such, asethylene glycol, propylene glycol, diethylene glycol, dipropyleneglycol, butylene glycol, 1,5-pentanediol, 1,6-hexanediol,octahydro-4,7-methano-1H-indenedimethanol or cyclohexane-1,2-, -1,3- or-1,4diol di(meth)acrylate; trimethylolpropane-di- or -tri(meth)acrylate;or pentaerythritol di-, tri- or tetra(meth)acrylate. As far as theamounts of higher-functional monomers (a21) are concerned, the commentsmade above with respect to the monomers (a2) apply.

Monomers (a22):

Ethylenically unsaturated monomers carrying at least one acid group,preferably a carboxyl group, per molecule, or a mixture of suchmonomers. As component (a22) it is particularly preferred to use acrylicacid and/or methacrylic acid. However, it is also possible to use otherethylenically unsaturated carboxylic acids having up to 6 carbon atomsin the molecule. Examples of such acids are ethacrylic acid, crotonicacid, maleic acid, fumaric acid and itaconic acid. It is also possibleto use ethylenically unsaturated sulfonic or phosphonic acids, or theirpartial esters, as component (a22). Further suitable monomers (a22) aremaleic acid mono(meth)acryloyloxyethyl ester, succinic acidmono(meth)acryloyloxyethyl ester and phthalic acidmono(meth)acryloyloxyethyl ester, and also vinylbenzoic acid; (allisomers), alpha-methylvinylbenzoic acid (all isomers) orvinylbenzenesulfonic acid (all isomers) Further examples ofacid-group-containing monomers (a22) are known from the laid-openspecification DE 196 25 773 A 1, column 2, line 58 to column 3, line 8,or from International Patent Application WO 98/49205, page 3, lines 23to 34.

Monomers (a23):

Vinyl esters of alpha-branched monocarboxylic acids having 5 to 18carbon atoms in the molecule. The branched monocarboxylic acids may beobtained by reacting formic acid or carbon monoxide and water witholefins in the presence of a liquid, strongly acidic catalyst; theolefins may be cracking products of paraffinic hydrocarbons, such asmineral oil fractions, and may comprise both branched and straight-chainacyclic and/or cycloaliphatic olefins. The reaction of such olefins withformic acid or with carbon monoxide and water produces a mixture ofcarboxylic acids in which the carboxyl groups are located predominantlyon a quaternary carbon atom. Other olefinic starting materials are, forexample, propylene trimer, propylene tetramer and diisobutylene.Alternatively, the vinyl esters may be prepared in a conventional mannerfrom the acids; for example, by reacting the acid with acetylene.Particular preference, owing to their ready availability, is given tothe use of vinyl esters of saturated aliphatic monocarboxylic acidshaving 9 to 11 carbon atoms which are branched on the alpha carbon atom.

Monomers (a24):

N,N-Diethylamino-alpha-methylstyrene (all isomers),N,N-diethylaminostyrene (all isomers), allylamine, crotylamine, 2-amino-or 2-N-methyl-, 2-N,N-dimethyl-, 2-N-ethyl-, 2-N,N-diethyl-,2-N-propyl-, 2-N,N-dipropyl-, 2-N-butyl-, 2-N-N-dibutyl-, 2-N-cyclohexylor 2-N,N-cyclohexyl-methyl-amino or 2-N,N,N,N-tetramethylammonium- or2-N,N-dimethyl-N,N-diethylammonium-, 2-tetramethylphosphonium or2-triethylsulfonium-ethyl acrylate, -ethyl methacrylate, -propylacrylate or -propyl methacrylate, or 3-amino-or 3-N-methyl-,3-N,N-dimethyl-, 3-N-ethyl-, 3-N,N-diethyl-, 3-N-propyl-,3-N,N-dipropyl-, 3-N-butyl-, 3-N,N-dibutyl-, 3-N-cyclohexyl- or3-N,N-cyclohexylmethylamino or 3-N,N,N,N-tetramethylammonium-or3-N,N-dimethyl-N,N-diethylammonium-, 3-tetra-methylphosphonium-or3-triethylsulfoniumpropyl acrylate or -propyl methacrylate.

Monomers (a25):

Diarylethylenes, especially those of the general formula V:R¹R²C=CR³R⁴  (V),in which the radicals R¹, R², R³ and R⁴ in each case independently ofone another are hydrogen atoms or substituted or unsubstituted alkyl,cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl,cycloalkylaryl, arylalkyl or arylcycloalkyl radicals, with the provisothat at least two of the variables R¹, R², R³ and R⁴ are substituted orunsubstituted aryl, arylalkyl or arylcycloalkyl radicals, especiallysubstituted or unsubstituted aryl radicals. Examples of suitable alkylradicals are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl,tert-butyl, amyl, hexyl or 2-ethylhexyl. Examples of suitable cycloalkylradicals are cyclobutyl, cyclopentyl or cyclohexyl. Examples of suitablealkylcycloalkyl radicals are methylenecyclohexane, ethylenecyclohexaneor propane-1,3-diylcyclohexane. Examples of suitable cycloalkylalkylradicals are 2-, 3- or 4-methyl-, -ethyl-, -propyl- or-butylcyclohex-1-yl. Examples of suitable aryl radicals are phenyl,naphthyl or biphenylyl, preferably phenyl and naphthyl and especiallyphenyl. Examples of suitable alkyl aryl radicals are benzyl or ethylene-or propane-1,3-diylbenzene. Examples of suitable cycloalkylaryl radicalsare 2-, 3- or 4-phenylcyclohex-1-yl. Examples of suitable arylalkylradicals are 2-, 3- or 4-methyl-, -ethyl-, -propyl- or -butylphen-1-yl.Examples of suitable arylcycloalkyl radicals are 2-, 3- or4-cyclohexylphen-1-yl. The aryl radicals R¹, R², R³ and/or R⁴ arepreferably phenyl or naphthyl radicals, especially phenyl radicals. Thesubstituents that may be present in the radicals R¹, R², R³ and/or R⁴are electron withdrawing or electron donating atoms or organic radicals,especially halogen atoms, nitrile, nitro, partially or fully halogenatedalkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl,cycloalkylaryl, arylalkyl and arylcycloalkyl radicals; aryloxy, alkyloxyand cycloalkyloxy radicals; arylthio, alkylthio and cycloalkylthioradicals and/or primary, secondary and/or tertiary amino groups.Diphenylethylene, dinaphthaleneethylene, cis- or trans-stilbene,vinylidene-bis(4-N,N-dimethylaminobenzene),vinylidene-bis(4-aminobenzene) or vinylidene-bis(4-nitrobenzene),especially diphenylethylene (DPE), are particularly advantageous and soare used with preference. In the context of the present invention, themonomers (a25) are used in order to regulate the copolymerizationadvantageously such that batchwise free-radical copolymerization is alsopossible.Monomers (a26):

Cyclic and/or acyclic olefins such as ethylene, propylene, but-1-ene,pent-1-ene, hex-1-ene, cyclohexene, cyclopentene, norbornene, butadiene,isoprene, cyclopentadiene and/or dicyclopentadiene.

Monomers (a27):

Amido-containing monomers such as (meth)acrylamides such as(meth)acrylamide, N-methyl-, N,N-dimethyl-, N-ethyl-, N,N-diethyl-,N-propyl-, N,N-dipropyl-, N-butyl-, N,N-dibutyl-, N-cyclohexyl-,N,N-cyclohexylmethyl- and/or N-methylol-, N,N-dimethylol-,N-methoxymethyl-, N,N-di(methoxymethyl)-, N-ethoxymethyl- and/orN,N-di(ethoxyethyl)-(meth)acrylamide; monomers containing carbamategroups, such as (meth)acryloyloxyethyl carbamate or(meth)acryloyloxypropyl carbamate; or monomers containing urea groups,such as ureidoacrylate or ureidomethacrylate.

Monomers (a28):

Monomers containing epoxide groups, such as the glycidyl ester ofacrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleicacid, fumaric acid and/or itaconic acid.

Monomers (a29):

Vinylaromatic hydrocarbons such as styrene, vinyltoluene,diphenylethylene or alpha-alkylstyrenes, especially alpha-methylstyrene.

Monomers (a210):

Nitriles such as acrylonitrile and/or methacrylonitrile.

Monomers (a211):

Vinyl compounds, especially vinyl halides and/or vinylidene dihalides,such as vinyl chloride, vinyl fluoride, vinylidene dichloride orvinylidene difluoride; N-vinyl amides such as vinyl-N-methylformamide,N-vinylcaprolactam or N-vinylpyrrolidone; 1-vinylimidazole; vinyl etherssuch as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether,n-butyl vinyl ether, isobutyl vinyl ether and/or vinyl cyclohexyl ether;and/or vinyl esters such as vinyl acetate, vinyl propionate, vinylbutyrate, vinyl pivalate and/or the vinyl ester of2-methyl2-ethylheptanoic acid.

Monomers (a212):

Allyl compounds, especially allyl ethers and allyl esters such as allylmethyl, ethyl, propyl or butyl ether or allyl acetate, propionate orbutyrate.

Monomers (a213)

Polysiloxane macromonomers having a number-average molecular weight Mnof from 1000 to 40,000 and having on average from 0.5 to 2.5ethylenically unsaturated double bonds per molecule; especiallypolysiloxane macromonomers having a number-average molecular weight Mnof from 2000 to 20,000, with particular preference from 2500 to. 10,000,and in particular from 3000 to 7000 and having on average from 0.5 to2.5, preferably 5 from 0.5 to 1.5, ethylenically unsaturated doublebonds per molecule, as are described in DE 38 07 571 A 1 on pages 5 to7, in DE 37 06 095 A 1 in columns 3 to 7, in EP 0 358 153 B 1 on pages 3to 6, in U.S. Pat. No. 4,754,014 A 1 in columns 5 to 9, in DE 44 21 823A 1 or in International Patent Application WO 92/22615 on page 12, line18 to page 18, line 10.

Monomers (a214):

Acryloxysilane-containing vinyl monomers, preparable by reactinghydroxy-functional silanes with epichlorohydrin and subsequentlyreacting the reaction product with (meth)acrylic acid and/orhydroxyalkyl esters and/or hydroxycycloalkyl esters of (meth)acrylicacid and/or further hydroxyl-containing monomers (a2).

Particularly preferred monomers (a2) are the monomers (a21), (a22) and(a29).

The methacrylate copolymer solutions for use in accordance with theinvention are standard commercial products and are sold, for example, bythe company BASF Coatings AG under the tradename Glasurit® Racing Clear923-144.

The preparation of the (meth)acrylate copolymers for use in accordancewith the invention has no special features as to its process but insteadtakes place with the aid of the methods, customary and known in thepolymers field, of continuous or batchwise free-radically initiatedcopolymerization in bulk, solution, emulsion, miniemulsion ormicroemulsion under atmospheric or superatmospheric pressure in stirredvessels, autoclaves, tube reactors, loop reactors or Taylor reactors attemperatures from 50 to 200° C.

Examples of suitable copolymerization techniques are described in patentapplications DE 197 09 465 A 1, DE 197 09 476 A 1, DE 28 48 906 A 1, DE195 24 182 A 1, DE 198 28 742 A 1, DE 196 28 143 A 1, DE 196 28 142 A 1,EP 0 554 783 A 1, WO 95/27742, WO 82/02387 and WO 98/02466.

Examples of suitable free-radical initiators are dialkyl peroxides, suchas di-tert-butyl peroxide or dicumyl peroxide; hydroperoxides, such ascumene hydroperoxide or tert-butyl hydroperoxide; peresters,such astert-butyl. perbenzoate, tert-butyl perpivalate, tert-butylper-3,5,5-trimethylhexanoate or tert-butyl per-2-ethylhexanoate;peroxodicarbonates; potassium, sodium or ammonium peroxodisulfate; azoinitiators, examples being azodinitriles such as azobisisobutyronitrile;C-C-cleaving initiators such as benzopinacol silyl ethers; or acombination of a nonoxidizing initiator with hydrogen peroxide. It isalso possible to use combinations of the above-described initiators.

Further examples of suitable initiators are described in German PatentApplication DE 196 28 142 A 1, page 3, line 49 to page 4, line 6.

It is preferred to add comparatively large amounts of free-radicalinitiator, the fraction of the initiator in the reaction mixture, basedin each case on the total amount of the monomers (a) and of theinitiator, being with particular preference from 0.2 to 20% by weight,with very particular preference from 0.5 to 15% by weight, and inparticular from 1.0 to 12% by weight.

It is additionally possible to use thiocarbonylthio compounds ormercaptans such as dodecyl mercaptan as chain transfer agents ormolecular weight regulators.

The organic solution (F) is present in the solution of the invention inan amount, based on the solution of the invention, of from 0.5 to 5,preferably from 1 to 4, and in particular from 2 to 3,% by weight.

A particularly advantageous solution of the invention comprises

-   -   39% by weight butyl acetate (from 98 to 100% pure),    -   38.77% by weight 1-methoxypropyl 2-acetate,    -   19.5% by weight xylene,    -   0.2% by weight ethanol (denatured with 1% by weight methyl ethyl        ketone),    -   0.03% by weight leveling gent containing siloxane groups, and    -   2.5% by weight methacrylate copolymer solution with a solids        content of 65% by weight.

The spot blender of the invention is free from toluene and is notsubject to any labeling requirement.

The preparation of the solution of the invention has no special featuresas to its method but instead takes place by mixing the constituents inan appropriate stirring vessel.

The solution of the invention is used as a spot blender in the processof the invention.

The process of the invention comprises the following steps:

-   (1) cleaning the damage site and its surroundings,-   (2) sanding and recleaning the damage site,-   (3) if desired, filling, sanding and cleaning the damage site,-   (4) applying a filler and flashing off the resultant filler film, or    alternatively curing the filler film and sanding and cleaning the    resultant filler coat,-   (5) applying a basecoat material to the filler film or filler coat,    flashing off the resultant basecoat film, and removing any    overspray,-   (6) applying a clearcoat material wet-on-wet to the basecoat film,-   (7) applying a spot blender, and-   (8) curing the applied films.

For the process of the invention it is essential that the basecoatmaterial is applied hidingly by pneumatic application with a spray gunfrom the outside, i.e. from the original finish, inward, i.e. toward thecenter of the damage site. It is further essential that the spot blenderused comprises the solution of the invention described in detail above.

For the pneumatic application of the coating materials it is possibleper se to use customary and known spray guns. In accordance with theinvention, however, it is of advantage to use smaller spray guns thanthe customary and known spray guns. Small-size spray guns of this kindare available from the company SATA, Kornwestheim, under the tradenameSATA minijet 2 HVLP SR (spot repair).

For the cleaning and sanding it is possible to use the cleaningequipment and cleaning fluids and the sanding and/or polishing equipmentthat is normally used for automotive refinishing.

For filling it is possible to employ customary and known knifing fillerssuch as those from the company Sikkens.

Suitable fillers are customary and known, aqueous and conventionalfillers, as described, for example, in patents and patent applicationsU.S. Pat. No. 4,537,926 A, EP 0 529 335 A 1, EP 0 595 186 A 1, EP 0 639660 A 1, DE 44 38 504 A 1, DE 43 37 961 A 1, WO 89/10387, U.S. Pat. No.4,450,200 A, U.S. Pat. No. 4,614,683 A and WO 94/26827.

The fillers are standard commercial products, which are sold, forexample, by the company BASF Coatings AG under the brand name Glasurit®Wasserfüller 70-71 or 1K-Grundfüller 76-71.

Examples of suitable conventional and aqueous basecoat materials areknown from patent applications EP 0 089 497 A 1, EP 0 256 540 A 1, EP 0260 447 A 1, EP 0 297 576 A 1, WO 96/12747, EP 0 523 610 A 1, EP 0 228003 A 1, EP 0 397 806 A 1, EP 0 574 417 A 1, EP 0 531 510 A 1, EP 0 581211 A 1, EP 0 708 788 A 1, EP 0 593 454 A 1, DE-A-43 28 092 A 1, EP 0299 148 A 1, EP 0 394 737 A 1, EP 0 590 484 A 1, EP 0 234 362 A 1, EP 0234 361 A 1, EP 0 543 817 A 1, WO 95/14721, EP 0 521 928 A 1, EP 0 522420 A 1, EP 0 522 419 A 1, EP 0 649 865 A 1, EP 0 536 712 A 1, EP 0 596460 A 1, EP 0 596 461 A 1, EP 0 584 818 A 1, EP 0 669 356 A 1, EP 0 634431 A 1, EP 0 678 536 A 1, EP 0 354 261 A 1, EP 0 424 705 A 1, WO97/49745, WO 97/49747, EP 0 401 565 A 1 and EP 0 817 684, column 5,lines 31 to 45. It is also possible to use the basecoat materials on thebasis of the mixer system described in European Patent Application EP 0578 645 A 1.

The basecoat materials are standard commercial products which are sold,for example, by the company BASF Coatings AG under the brand namesGlasurit® topcoat series 55 with Glasurit® standardizing additive 352-91or Glasurit® topcoat series 90 with Glasurit® standardizing additive93-E 3 and Glasurit® blender 90-M5 in accordance with European PatentApplication. EP 0 578 645 A 1.

As clearcoat materials it is possible to use all customary and knowntwo-component clearcoats based on standard commercialhydroxyl-containing binders, such as those described above, for exampleGlasurit® Racing-Clear 923-144, and polyisocyanates such as Glasurit® MShardener 929-71 (both from the company BASF Coatings AG).

The curing of the applied coating materials likewise has no specialmethods but takes place using customary and known equipment such asradiant heaters which use near or far infrared light, or fan heaters.

The process of the invention is particularly suitable for the spotrepair of damaged areas up to 3 cm in diameter. The damage site shouldbe without deformations such as dents, scratches or stone chips. Spotrepair on vertical surfaces is particularly advisable. In the case ofhorizontal surfaces, the process of the invention is advantageouslyemployed in the vicinity of edges (distance up to 15 cm).

The process of the invention makes it possible to reduce sanding and/orpolishing times by more than 50% as compared with conventionaltechniques. It gives refinishes which do not stand out visually fromthe. original finish. Tearing or breakaway of the repair clearcoat inthe runout zones is no longer observed. The quality of the refinishes issuch that they may also be used for in-plant automotive spot repair oforiginal finishes. Because of the high pass rate, considerable economicadvantages are achieved.

In order to facilitate training and the implementation of the process ofthe invention for paintshop users or in-plant users at the automaker,the set of the invention is provided. The set of the inventioncomprises:

-   -   a metal case and/or a scratch-resistant stable plastic,    -   in the base of the case, a foam inlay with a depression in the        center and two depressions symmetrically left and right thereof,        -   the depression in the center containing a can, preferably a            0.5 1 can, of the ready-to-spray solution of the invention            and        -   the two depressions left and right thereof each containing a            small spray gun, especially the small-sized spray gun SATA            minijet 2 HVLP SR from SATA, Kornwestheim, for implementing            the process of the invention,    -   a foam inlay in the lid of the case, containing        -   a manual and a CD-ROM which describe the process of the            invention in detail.

Furthermore, the set of the invention may also include a recommendationlist for other products and apparatus, as commonly used in automotiverefinishing.

The dimensions of the case are such that the spray guns and the can maybe presented attractively and eyecatchingly without close confinement.Furthermore, the inlays and the depressions are designed such that thecan, the spray guns, the manual and the CD-ROM are securely housed. Byvirtue of the set of the invention, the skilled worker is presented incompact form with all of the technical information and apparatus whichhe or she needs for training and: for; implementing the process of theinvention. This greatly facilitates the introduction of the process ofthe invention into practice, so that within the paintshop there are alsono safety problems affecting its introduction and implementation.

EXAMPLES Example 1

The Preparation of a Solution of the Invention

A solution of the invention was prepared by mixing the followingconstituents:

-   -   39 parts by weight butyl acetate (from 98 to 100% pure),    -   38.77 parts by weight 1-methoxypropyl 2-acetate,    -   19.5 parts by weight xylene,    -   0.2 parts by weight ethanol (denatured with 1% by weight methyl        ethyl ketone),    -   0.03 parts by weight leveling agent containing siloxane groups        (Baysilon® OL 44; 100% pure), and    -   2.5 parts by weight methacrylate copolymer solution made from        hydroxypropyl methacrylate, butyl methacrylate, styrene,        methacrylic acid and methyl methacrylate in butyl acetate (98 to        100% pure) and Solvesso® 100 (solids content: 65% by weight)        (Glasurit® Racing Clear 923-144)

The solution was outstandingly suitable as a spot blender.

Example 2

Automotive Spot Repair to the Bumper of a Nissan Almera

The damage site was a 4 to 5 cm long scratch in the rear bumper whichhad been caused by a key and which in part extended down to thesubstrate. The equipment, materials and steps employed were as follows.

Cleaning:

-   1. Spray can with Teroson intensive screen cleaner-   2. Finish control spray 55535 from 3M-   3. Spray flask with nitro diluent M600 from Akzo-   4. Kimberley Clark Classic cleaning cloths    Sanding:

Sander

Sanding pad P 1500 from 3M

Filling:

Knifing filler from Sikkens in the combination filler tube

Flash-off time: 10 minutes/20° C.

Sanding: wet (spray flask) with sanding pad P 1000 from 3M

Masking Off:

Paper and masking tape from 3M

Basecoat:

Glasurit® topcoat series 55-NIS AV3 from BASF Coatings AG with red pearleffect

Spray gun: SATA minijet green (1.0 NR); spray pressure: 1.5 bar

Damage site sprayed hidingly from the outside toward the center andrunning out extensively into the area

Flashing off: two to three minutes

Clearcoat:

Glasurit® clearcoat 923-155 comprising Glasurit® Racing Clear 923-144,Glasurit® MS hardener 929-71 and Glasurit® standardizing additive 352-91(mixing ratio: 2:1 +10%)

Spray gun: SATA minijet NR 2000

Damage site sprayed running out over the -end face of the bumper

Spot Blender of Example 1:

Spray gun: SATA minijet NR 2000

Damage site sprayed over the runout zones of the clearcoat in the regionof the left-hand and right-hand corner of the bumper

Drying:

Infrared emitter, 20 minutes, 50% of maximum intensity

Polishing:

No polishing needed

After this, even without polishing, the damage site had beenoutstandingly matched to the original finish, both optically andmechanically.

Example 3

Automotive Spot Repair to the Fender of a Nissan Almera

The damage site was a scratch on the front left-hand fender above thewheel arch. The equipment, materials and steps employed were as follows.

Cleaning:

Glasurit® cleaner 700-1 spray bottle

Kimberley Clark Classic cleaning cloths and Hamach dust-binding cloth

Sanding:

Wet (spray bottle) with touch-and-close-backed sandpaper from the NissanUK OEM coating line (SIA P1500)

Surface check with the fingers

Filling:

Knifing filler from Sikkens, in the combination filler tube

Flash-off time: 10 minutes/20° C.

Sanding:

Wet (spray bottle) with touch-and-close-backed sandpaper from the NissanUK OEM coating line (SIA P1500)

Surface check with the fingers

Dry with Scotch-Brite gray

Masking Off:

Paper and masking tape from 3M

Pockets and rounded, soft edges

Basecoat:

Glasurit® topcoat series 90-NIS BT3 from BASF Coatings AG with bluepearl effect

Spray gun: SATA minijet NR 2000; spray pressure: 2 bar

Damage site sprayed hidingly from the outside toward the center andrunning out extensively into the area

Flashing off: two to three minutes

Clearcoat:

Glasurit® clearcoat 923-155 comprising Glasurit® Racing Clear 923-144,Glasurit® MS hardener 929-71 and Glasurit® standardizing additive 352-91(mixing ratio: 10 2:1 +10%)

Spray gun: SATA minijet NR 2000; spray pressure: 2 bar

Damage site, sprayed running out over the end face of the bumper

Spot Blender of Example 1:

Spray gun: SATA minijet NR 2000

Damage site sprayed left and right over the runout zones of theclearcoat

Polishing:

Drop mark is sanded (bodywork file)

Polishing: with 09639 Finesse from 3M with air-pressure-operatedpolishing machine with small plate and sponge from 3M

Polish: with 03990 Imperial from 3M by hand with polishing cloths

After this, the damage site had been outstandingly matched to theoriginal finish, both optically and mechanically.

1. A binder solution comprising, based on the binder solution, (A) from30 to 50% by weight of at least one member selected from the groupconsisting of alkyl acetate, cycloalkyl acetate, and mixtures thereof,wherein one or both of the alkyl radical or cycloalkyl radical have from3 to 10 carbon atoms, (B) from 30 to 50% by weight of at least onemember selected from the group consisting of alkoxyalkyl acetate,cycloalkoxyalkyl acetate, alkoxycycloalkyl acetate,cycloalkoxycycloalkyl acetate, and mixtures thereof, wherein the alkoxyradicals and the alkyl radicals have from 1 to 6 carbon atoms and thecycloalkoxy radicals and cycloalkyl radicals have from 3 to 10 carbonatoms, (C) from 10 to 30% by weight of at least one alkylaromaticcompound having at least two alkyl radicals of 1 to 6 carbon atoms, (D)from 0.01 to 1% by weight of at least one alcohol of 1 to 6 carbon atomsin the molecule, (E) from 0.005 to 1% by weight of at least oneadditive, and (F) from 0.5 to 5% by weight of an organic solution atleast one (meth)acrylate copolymer having a solids content, based on thesolution (F), of from 50 to 90% by weight.
 2. The binder solution ofclaim 1, comprising, based on the binder solution, from 35 to 45% byweight of at least one alkyl acetate (A) of 3 to 5 carbon atoms in thealkyl radical.
 3. The binder solution of claim 1, comprising, based onthe binder solution, from 30 to 45% by weight of at least onealkoxyalkyl acetate (B) having from 1 to 3 carbon atoms in the alkoxyradical and 2 to 4 carbon atoms in the alkyl radical.
 4. The bindersolution of claim 1, comprising, based on the binder solution, from 15to 25% by weight of at least one alkylaromatic compound (C) having from2 to 3 methyl groups in the molecule.
 5. The binder solution of claim 1,comprising, based on the binder solution, from 0.1 to 0.4% by weight ofan alcohol (D) selected from the group consisting of methanol, ethanol,propanol, isopropanol, and mixtures thereof.
 6. The binder solution ofclaim 1, comprising, based on the binder solution, from 0.01 to 0.5% byweight of at least one additive (E) selected from the group consistingof welling agents.
 7. The binder solution of claim 1, comprising, basedon the binder solution, from 1 to 3% by weight of at least one organicsolution (F) of a (meth)acrylate copolymer having a solids content,based on the solution (F), of from 60 to 70% by weight.
 8. The bindersolution of claim 1, wherein (A) is butyl acetate.
 9. The bindersolution of claim 1, wherein (B) is 1-methoxypropyl 2-acetate.
 10. Thebinder solution of claim 1, wherein (C) is_xylene.
 11. The bindersolution of claim 1, wherein (D) is_ethanol.
 12. The binder solution ofclaim 1, wherein the methacrylate copolymer has a hydroxyl number>100 mgKOH/g.
 13. A method of automotive spot repair comprising applying thebinder solution of claim 1 to a previously coated substrate.
 14. Anautomotive spot repair process comprising the steps of (1) cleaning adamaged site and an area surrounding said site, (2) sanding the damagedsite, (3) applying a filler to provide a filler film, (4) applying abasecoat composition to the filler film to provide a basecoat film, (5)applying a clearcoat composition wet-on-wet to the basecoat film toprovide a clearcoat film, (6) applying a spot blender, and (7) curingthe basecoat and clearcoat films, wherein the basecoat material isapplied hidingly by pneumatic application with a spray gun, and saidspot blender comprises the binder solution of claim
 1. 15. A spot repairset comprising a case comprising a ready-to-spray container of thebinder solution of claim 1 and a spray gun.
 16. The process of claim 14further comprising one or more additional steps selected from the groupconsisting of filling, sanding, cleaning, and mixtures thereof.
 17. Theprocess of claim 14 wherein the step of applying a filler furthercomprises flashing off the filler film.
 18. The process of claim 14wherein the step of applying a filler further comprises curing thefiller film to provide a cured filler film.
 19. The process of claim 18further comprising sanding the cured filler film.
 20. The process ofclaim 14 further comprising flashing off the basecoat film and removingany overspray.
 21. The spot repair set of claim 15 wherein the casefurther comprises a foam inlay for holding one or more of theready-to-spray container, the spray gun or the material describing theprocess.
 22. The spot repair set of claim 15, further comprising amaterial describing a process, the material, selected from the groupconsisting of manuals, CD-ROMs, and mixtures thereof.